Apparatus and method for improving fuel efficiency of gasoline engines

ABSTRACT

Apparatus for supplying air-and-gasoline vapor mixture from the ullage space in a gas tank above the gasoline therein through a safety cannister and a shut-off valve to two &#34;gang&#34; valve assemblies that divide the vapor into individual flows that are delivered directly to the intake valves of the individual cylinders of a piston-and-cylinder engine, by-passing the carburetor and the intake manifold. The gas tank is aerated through a vent pipe having on one end an air filter open to outside air and on the other end an aerator submerged in the gasoline, and the fuel-vapor mixture is directed into the intake ports of the intake valves by heat-resistant nozzle tubes.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 08/232,943, filedApr. 22, 1994, which is incorporated herewith by reference, now U.S.Pat. No. 5,522,368.

BACKGROUND OF THE INVENTION

This invention relates generally to internal combustion engines and morespecifically to an apparatus and method for supplying the fuel-airmixture to a gasoline-powered engine.

It is well known that gasoline-powered internal combustion engines ofthe piston-and-cylinder type are used throughout the world in largenumbers to drive various mechanisms, most notably automobiles and othervehicles. Matters of great concern are the fuel-burning efficiency, andthus economy, of such engines and the amounts of harmful emissions theyintroduce into the atmosphere. Accordingly, great efforts have been madeto improve the operating efficiency of such engines, both for bettereconomy and for reduced emissions.

Among the prior efforts are the apparatus disclosed in U.S. Pat. No.4,011,487 in which air bubbles are introduced from a compressor, ordrawn by engine vacuum, through a supply of gasoline and conducteddirectly to the carburetor or intake manifold of a gasoline engine. In avariation disclosed in U.S. Pat. No. 3,931,801, exhaust gases arebubbled through the fuel to heat and vaporize it for mixing with air atthe inlet of an intake manifold. U.S. Pat. No. 3,800,768 discloses anapparatus for reducing exhaust emissions during start-up, warm-up,idling and high-speed operation, by bubbling air through the gasoline toproduce a mixture that by-passes the carburetor and is directed to afuel intake system between the carburetor and the engine. A carburetorsupplies the engine at other times during normal operation.

While these and other prior approaches may have had some success inimproving fuel economy and reducing emissions, none seem to have metwith commercial success or to have gained general acceptance, perhapsbecause of their complexity, relatively high expense, or otherdisadvantages. The general objective of this invention is to provide anew and improved method and apparatus for use in conjunction withgasoline-powered engines to improve their fuel efficiency, the apparatusbeing relatively simple, inexpensive and readily adaptable forautomobiles, either as original equipment or for later installation.

SUMMARY OF THE INVENTION

The present invention provides a relatively simple and inexpensiveapparatus, and related method, for producing a fuel mixture of gasolinevapor and air in the fuel supply of an automobile, including the fueltank, and by-passing the conventional fuel supply system of the engineto deliver the fuel mixture directly to the intake valve in eachcylinder of the engine. The result of this novel approach is tosignificantly increase the fuel efficiency of the engine,correspondingly reducing the gasoline consumption in operation, andreducing exhaust emissions and resultant air pollution.

More specifically, the invention introduces a flow of air to the gastank "ullage", the space in the gas tank above the liquid gasolinetherein, draws an air-and-gasoline vapor mixture from the ullage ingaseous form and conducts this mixture through a safety reservoirinterposed between the tank and the engine, and introduces the vapormixture directly into each of the cylinders of the gasoline-poweredengine through appropriate valving for dividing the flow into therequisite number of individual flows and delivering these flows to theintake valves of the respective cylinders. The valving preferablyincludes flow adjustment means for balancing the flows to the cylinders.

Accordingly, the invention by-passes the usual fuel supply system,whether it is a carburetor, a fuel injection device or otherwise, anddelivers the vapor mixture directly to the intake valve. The result hasbeen a dramatic improvement in fuel efficiency and emissions obtained ina conventional automobile.

Other aspects and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying exemplary drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a gas-saving apparatus embodying thepresent invention shown with parts of a gasoline-powered automobileengine;

FIG. 2 is an enlarged cross-sectional view taken in a vertical planethrough the gas tank shown in FIG. 1, with an aerator in the gas tank;and

FIG. 3 is an enlarged fragmentary cross-sectional view taken through thevalving and one of the cylinders of the automobile engine shown in FIG.1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in the drawings for purposes of illustration, the invention isincorporated in a gas-saving apparatus, indicated generally by thereference number 10 in FIG. 1, for supplying a fuel-air mixture from agas tank 11 to a gasoline-powered internal combustion engine 12 of thepiston-and-cylinder type, herein shown as an eight-cylinder "V-8" enginehaving an air cleaner 13, a carburetor 14 and spark plugs showngenerally at 15. The gas tank has an upright fill pipe 17 with an openupper end that is accessible from outside the vehicle and normally isclosed and sealed by a cap 18.

In piston-and-cylinder engines, each of the cylinders 19 (see FIG. 3)houses a piston 20 and is closed at one end by a head 21 whichcooperates with the cylinder and the piston in defining a combustionchamber 22. An intake valve 23 normally closes intake port 25 but opensto permit the flow of the fuel-air mixture into the chamber when theintake port 25 is opened. An exhaust valve (not shown) is provided forthe flow of combustion products out of the chamber when the exhaustvalve is opened, all in a conventional manner.

The conventional fuel supply system uses the carburetor 14 to drawgasoline from the gas tank 11 into an air stream flowing to thecombustion chambers 22 during the intake ("down") strokes of the pistons20, to be exploded by the spark plugs 15 in the combustion chambersafter being compressed during the "up" or compression strokes of thepistons. Only the parts of the engine 12 that are important for anunderstanding of the invention are shown in the drawings, the otherparts being well known and conventional in construction and operation.

In accordance with the present invention, air is supplied to the"ullage" space 26 (FIG. 2) in the gas tank 11 above the level 27 of thebody of liquid fuel 28, and an air-and-gasoline vapor mixture is drawnout of the ullage space and through a safety reservoir in the form of acannister 29 (FIG. 1) to valving for dividing the vapor mixture intoindividual flows and delivering the flows directly to the intake valvesof the respective cylinders 19. Herein, the valving constitutes two"gang" valve assemblies 30 and 31, each of which serves four of theeight cylinders through connecting conduits 32 and nozzle tubes 33 (FIG.3). This system thus provides direct connections between the ullagespace 26 and the combustion chambers 22 of the cylinders 19, by-passingthe carburetor 14 of the vehicle, and by-passing the intake manifold.

More specifically, as shown in FIGS. 1 and 2, a constant supply of airis provided to the ullage space 26 through a vent pipe 34 and an airfilter 35 that is open to outside air. The vent pipe extends into thefill pipe 17, at a level above the gas tank 11, and extends downwardthrough the fill pipe to a lower end 38 near the bottom of the tank. Onthe lower end of the vent pipe is an aerator 39 through which air isadmitted into the tank.

In normal operation, air will be drawn into the gas tank by the suctioncreated by the cylinders 19, and will bubble up to the ullage space 26through the gasoline 28 in the tank 11. The natural vaporization of thegasoline, augmented by the "sloshing" movement of the body of gasolinein the tank, produces a high concentration of gasoline vapor in theullage space, including the interior of the fill pipe 17. It isimportant for proper operation that the gas tank be filled only to apredetermined maximum level, as shown at 27, below the top of the tank,leaving a substantial space for the ullage.

It is to be understood that the carburetor 14 should be rendered inoperational during use of the apparatus of the invention, except thatthe conventional accelerator pump (not shown) of the carburetor willremain operational to initiate operation, creating the vacuum that willdraw the air-gasoline vapor mixture from the ullage space 26 and to theengine 12. Disabling of the carburetor may be accomplished in variousways, but most simply by closing the air and fuel jets in thecarburetor. This leaves the accelerator pump operational, because itsoutput is independent of the air and fuel jets.

As shown in FIG. 1, the cannister 29 is disposed between the engine 12and the gasoline tank 11, preferably inside the engine compartment (notshown), and is connected to the engine by a fuel supply line having afirst section 41 that opens at one end into the fill pipe 17 and at theother end into the upper portion of the cannister 29 through the topthereof. A continuation 42 of the fuel supply line extends out of thetop of the cannister to carry the air-and-gasoline vapor mixture to theengine 12. This cannister prevents any accidental delivery of liquidgasoline to the engine. The cannister may be a simple fluid-tightcontainer with a capacity of two quarts or less of liquid.

From the cannister 29, the continuation 42 of the fuel supply line leadsto a "T" connection 44 that divides the fuel supply flow into two lines45 and 46, one extending to each of the valve manifolds 30, 31 fordelivery to the associated bank of cylinders 19. A control valve 47preferably is installed in the fuel supply line, herein shown near theexit of the line 42 from the cannister 29, to provide means foradjusting the volume of the flow through the line 42 or to close theline entirely if, for any reason, operation of this fuel supply systemis to be stopped. This valve is shown schematically as a manual valve,but may be automatically controlled as well.

Since four cylinders 19 are served by each of the "gang" valveassemblies 30, 31, four supply conduits 32 extend from each valveassembly to the associated cylinders 19, communicating between the valveassembly and the interior of the head 21 of the engine 12. While thesevalve assemblies may take various forms, the simple form shown in FIGS.1 and 3 to illustrate the invention comprises a block-like elongatedbody 49 having a central longitudinal bore 50 into which the line 45opens through a threaded fitting 51 in one end of the body. Four outletports 52 are spaced apart along the bore with four needle valveoperators 53 threaded into the body and projecting into the bore inopposed relation with the four ports. A coiled spring 54 is fittedaround the stem of each needle-valve operator and is compressed betweenthe body 49 and a head on the operator, thereby holding each operatorwith its inner end "open" in a selected "open" position relative to itsassociated port 52. This permits the adjustment of all of the valves tobalance the flows to the cylinders 19.

To deliver these flows to the cylinders 19, each valve port 52communicates with the upper end portion of the cylinder through one ofthe conduits 32, connected at one end to a fitting 55 threaded into theunderside of the body 49 and at the other end to a nozzle tube 33composed of heat resistant material, such as copper tubing. The tubesare fitted at their outer ends in the conduits 32 and extend throughbores 57 into the intake manifold of the head 21, with their inner ends58 forming outlets positioned close to and bent toward the intake port25 of the associated cylinder 19. Accordingly, there is a direct fuelsupply path from the cannister 29 to the intake port of each of thecylinders and, when the intake valve 23 is in the "open" position, tothe combustion chamber 22 of the cylinder.

The result is the very efficient delivery of the air-gasoline vapormixture directly to the intake port 25 and thence into the combustionchamber 22. This is believed to be very important for accomplishing theadvantages of the present invention.

To demonstrate the effectiveness of the invention, the apparatus asabove described has been installed in a conventional automobile with agasoline-powered engine, specifically a 1979 Pontiac "Bonneville"station wagon with an eight-cylinder V-8 engine. It was found that fuelefficiency improved from approximately nine miles per gallon ("mpg") tovalues in the range of fifteen to twenty-seven mpg, depending upon thespecific circumstances of operation, and hydrocarbon emissions werereduced from 200 to 300 parts per million (ppm) to twenty-three ppm,while carbon emissions were reduced from 1.0 to 0.5 percent. Theconventional carburetor remained in the vehicle but its air and fueljets were closed, leaving its accelerator pump operative for use instart-up and to create the vacuum that draws the air-and-gasoline vapormixture through the cannister 29 to the valves and the engine. Theinvention provided all of the fuel-air mixture used by the engine 12except that provided by the accelerator pump, producing the exceptionalimprovements as described.

The method of the invention will be evident from the foregoing detaileddescription of the apparatus, with the method steps described as well.In general, the method comprises the steps of providing the elements ofthe apparatus so as to produce the air-gasoline vapor mixture in theullage space 27 and to divide the mixture into individual flows anddeliver each flow to the combustion chambers of one of the cylinders 19through a nozzle pipe 33 for discharge close to the intake port 25 ofthat cylinder. Aeration of the gasoline through the vent pipe 34,passage of the mixture through the cannister 29, balancing of theindividual flows with the adjustable valve assemblies 30 and 31 aredetailed secondary aspects of the method of the invention.

From the foregoing, it will be seen that the apparatus of the inventionis quite simple and inexpensive in construction and operation, and boththe method and the apparatus provide a novel approach to the delivery ofthe air-and-gasoline vapor to the cylinders of a gasoline-poweredengine. It also will be evident that, while one particular embodiment ofthe invention has been illustrated and described in detail, variousmodifications, changes and additions will become apparent to thoseskilled in the art.

I claim as my invention:
 1. An apparatus for improving the fuelefficiency of an internal combustion engine, said engine having aplurality of cylinders with pistons housed therein, said pistonscooperating with the cylinders to define a plurality of combustionchambers, said engine having an intake valve opening into each of saidcombustion chambers and an intake port for each intake valve, saidengine being operably connected to a vehicle having a gasoline tank witha fill pipe for admitting gasoline into the tank to a predeterminedlevel, comprising:means for admitting a supply of air into said gasolinetank; a fuel supply line communicating at one end with said gasolinetank above said predetermined level to receive a flow ofair-and-gasoline vapor mixture from the tank; a safety cannister in saidfuel supply line for collecting liquid gasoline from said flow; valvingcommunicating with said fuel supply line to receive said flow andoperable to divide the flow into a plurality of separate flows for saidplurality of cylinders; and a plurality of conduits directly connectedto said valving to receive said separate flows, said conduits includingnozzles positioned adjacent to said intake valves to deliver each of theflows directly to the intake port of the associated intake valve.
 2. Anapparatus for improving the fuel efficiency of an internal combustionengine, said engine having a plurality of cylinders with pistons housedtherein, said pistons cooperating with the cylinders to define aplurality of combustion chambers, said engine having an intake valveopening into each of said combustion chambers and an intake port foreach intake valve, said engine being operably connected to a vehiclehaving a gasoline tank with a fill pipe for admitting gasoline into thetank to a predetermined level, comprising:means for admitting a supplyof air into said gasoline tank; a fuel supply line communicating at oneend with said gasoline tank above said predetermined level to receive aflow of air-and-gasoline vapor mixture from the tank; valvingcommunicating with said fuel supply line to receive said flow andoperable to divide the flow into a plurality of separate flows for saidplurality of cylinders; and a plurality of conduits directly connectedto said valving to receive said separate flows, said conduits includingnozzles positioned adjacent to said intake valves to deliver each of theflows directly to the intake port of the associated intake valve,wherein said valving comprises: at least one valve body having a mainpassage for receiving the air-and-gasoline vapor mixture from saidsupply line, a predetermined number of outlet ports each communicatingwith said main passage to receive separate flows of the mixture,conduits from the outlet ports to the nozzles, and means forindividually adjusting and balancing the flows through the ports. 3.Apparatus for improving the fuel efficiency of a vehicle having agasoline tank adapted to be filled with gasoline to a predeterminedlevel, and an engine having at least one intake port for receiving anair-and-gasoline vapor mixture to power the vehicle, comprising:meansfor admitting air into the gasoline tank to form the air-and-gasolinevapor mixture in the ullage space in the tank above the gasoline; a fuelsupply line communicating at one end with the ullage space to receivethe vapor mixture therefrom and having an opposite end for deliveringthe vapor mixture to the engine, wherein said fuel supply line has asafety cannister therein for collecting liquid gasoline from said vapormixture; and valve assembly means communicating with said opposite endof the fuel supply line to receive the vapor mixture therefrom anddeliver the same to the engine, including a conduit terminating in anoutlet adjacent to the intake port to deliver the mixture directly tothe intake port.
 4. Apparatus for improving the fuel efficiency of avehicle having a gasoline tank adapted to be filled with gasoline to apredetermined level, and an engine having at least one intake port forreceiving an air-and-gasoline vapor mixture to power the vehicle,comprising:means for admitting air into the gasoline tank to form theair-and-gasoline vapor mixture in the ullage space in the tank above thegasoline; a fuel supply line communicating at one end with the ullagespace to receive the vapor mixture therefrom and having an opposite endfor delivering the vapor mixture to the engine; and valve assembly meanscommunicating with said opposite end of the fuel supply line to receivethe vapor mixture therefrom and deliver the same to the engine,including a conduit terminating in an outlet adjacent to the intake portto deliver the mixture directly to the intake port; wherein the engineis of the type having a plurality of cylinders each having an intakevalve including an intake port, and wherein said valve assembly meanscomprises valving for receiving the vapor mixture from the fuel supplyline and dividing the mixture into a plurality of flows, one for each ofthe intake ports, and a plurality of conduits each terminating in anozzle for directing the flow into the intake port of the associatedcylinder; further including adjustable valves in said valving forbalancing the flows to said conduits.
 5. A method for increasing thefuel efficiency of an engine supplied with gasoline from a gasoline tankand having a plurality of cylinders each having an intake valve with anintake port, comprising the steps of:supplying air and gasoline to thetank and forming an air-and-gasoline vapor mixture in the tank above thegasoline therein; withdrawing the vapor mixture from the tank andcarrying the mixture to the engine; dividing the vapor mixture into aplurality of flows, one for each cylinder; balancing the flows to eachof said cylinders; and delivering the flows to the cylinders byreleasing the flows close to the intake ports to be drawn directlytherein.
 6. An apparatus, comprising:a vehicle; a gasoline tank with afill pipe for admitting gasoline into the tank to a predetermined levelin said vehicle; an internal combustion engine operably connected tosaid vehicle, said engine having a plurality of cylinders with pistonshoused therein, said pistons cooperating with the cylinders to define aplurality of combustion chambers, said engine having an intake valveopening into each of said combustion chambers and an intake port foreach intake valve; a vent pipe for admitting a supply of air into saidgasoline tank; a fuel supply line communicating at one end with saidgasoline tank above said predetermined level to receive a flow ofair-and-gasoline vapor mixture from the tank; a safety cannister in saidfuel supply line for collecting liquid gasoline from said flow; valvingcommunicating with said fuel supply line to receive said flow andoperable to divide the flow into a plurality of separate flows for saidplurality of cylinders; and a plurality of conduits directly connectedto said valving to receive said separate flows, said conduits includingnozzles positioned adjacent to said intake valves to deliver each of theflows directly to the intake port of the associated intake valve. 7.Apparatus as defined in claim 1 wherein said means for admitting airinto said tank comprises a vent pipe communicating with the interior ofsaid tank from the outside thereof.
 8. Apparatus as defined in claim 7wherein said vent pipe extends into said tank and has a lower end nearthe bottom of the tank.
 9. Apparatus as defined in claim 8 furtherincluding an aerator on said vent pipe disposed in said tank below saidpredetermined level so as to be immersed in the gasoline therein. 10.Apparatus as defined in claim 1 wherein said cannister is a liquidcontainer having a top with an inlet and an outlet for the fuel supplyline.
 11. Apparatus as defined in claim 2 wherein said adjusting andbalancing means comprise adjustable needle valves for said ports. 12.Apparatus as defined in claim 2 wherein said nozzles compriseheat-resistant tubes having inner end portions directed toward theintake ports and positioned close to the ports to discharge theair-and-gasoline vapor mixture directly into the intake valve. 13.Apparatus as defined in claim 3 wherein the engine is of the type havinga plurality of cylinders each having an intake valve including an intakeport, and wherein said valve assembly means comprises valving forreceiving the vapor mixture from the fuel supply line and dividing themixture into a plurality of flows, one for each of the intake ports, anda plurality of conduits each terminating in a nozzle for directing theflow into the intake port of the associated cylinder.
 14. Apparatus asdefined in claim 13 wherein said conduits include tubes ofheat-resistant material and having inner outlet ends positioned close tothe intake ports.
 15. Apparatus as defined in claim 3 further includinga safety cannister in said supply line for collecting liquid gasoline.16. The method defined in claim 5 wherein the delivering step isperformed by conducting the flows into the engine and discharging eachflow close to and in the direction of the intake port.
 17. An apparatusaccording to claim 6, further comprising an aerator on said vent pipedisposed in said tank below said predetermined level so as to beimmersed in the gasoline therein.
 18. An apparatus according to claim 6,wherein said valving comprises:at least one valve body having a mainpassage for receiving the air-and-gasoline vapor mixture from saidsupply line, a predetermined number of outlet ports each communicatingwith said main passage to receive separate flows of the mixture,conduits from the outlet ports to the nozzles, and means forindividually adjusting and balancing the flows through said outletports.
 19. An apparatus according to claim 6, wherein said nozzlescomprise heat-resistant tubes having inner end portions directed towardthe intake ports and positioned close to the intake ports to dischargethe air-and-gasoline vapor mixture directly into the intake valve.